->'''Peter Petrelli:''' Do you know me?\\
'''Adam Monroe:''' Of course I know you. It's me, Adam. Don't you remember? You and I are going to change history.\\
-- ''Series/{{Heroes}}'', "Out of Time"

TheHero, or a member of the [[FiveManBand heroic band]], finds a {{Mentor}} with new secret techniques to teach. The student eagerly signs on, only to learn later that there's a catch -- the mentor is evil, has a hidden agenda of his or her own, and those new abilities are seriously nasty (though certainly not [[UselessSuperpowers useless]]). The student may feel [[MyGodWhatHaveIDone "soiled"]] by having learned these [[DangerousForbiddenTechnique techniques]] and might swear off ever using them again, or they might have to [[EvilFeelsGood wrestle with temptation]] against using them regularly. Of course, the audience fully expects that there will come a time of great need, and [[ChekhovsSkill out will come the evil technique]] because ItsTheOnlyWay.

The Evil Mentor might teach the character BlackMagic, a DangerousForbiddenTechnique, how to use a DeadlyUpgrade (while downplaying the costs), advanced PsychicPowers like MindRape or [[{{Brainwashed}} Mind Control]], and generally introduce them to abilities or substances that are [[ThisIsYourBrainOnEvil painfully addictive]] and make PsychoSerum seem safe to use by comparison.

The Evil Mentor's motivation for this are similar to those of an OldMaster, but with a ZenSurvivor's more elitist air: they're looking for someone to carry on their legacy, warts and all, and usually ''against'' the pupil's wishes because only ''they'' are "worthy enough" to learn it. This usually entails actively [[MoreThanMindControl corrupting the hero]], not just to spread evil and [[FallenHero deny good a powerful champion]], but also netting him a personal {{Dragon}}. The Evil Mentor is also patient enough to wait, hoping that if attempts to actively corrupt fail at forcing a FaceHeelTurn, then more passive temptation will do their work for them.

A variant is the Evil Mentor's [[TomeOfEldritchLore Book]], which is not evil ''per se'', but contains [[TheDarkSide dark-side-y]] formulas and things the student [[YouAreNotReady might not be ready to learn]]. Unless, y'know, it's an ArtifactOfDoom, in which case it's an Evil Mentor in book form.

Contrast DeceptiveDisciple, who turns "good" or honorable martial arts or powers on their head to achieve evil ends or inverts them into BlackMagic. See also BastardUnderstudy for a villain's voluntary apprentice.

If the mentor pretends to be a good mentor but is actually a villain out to exploit his student, he's a TreacherousAdvisor. The step-down of this trope is the BrokenPedestal, who trains the student well, but is eventually revealed to be bad or corrupt much to the student's chagrin.

%%Do not remove the folders, they are the standard.
----
[[foldercontrol]]

!!Examples:

[[folder:Anime & Manga]]
* The BigBad of ''{{Basilisk}}'', [[spoiler: Tenzen Yakushiji]], takes a boy in ([[spoiler: Koushirou Chikuma]]) and trains him as his apprentice and [[TheDragon right hand]], years before the events of the series start.
* ''[[KenichiTheMightiestDisciple History's Strongest Disciple Kenichi]]'' introduces a ''whole organization'' of these in the manga after the arc covered in the anime called Yami. Unlike Kenichi's masters, Yami stresses the value of martial arts as killing methods. One member in particular [[spoiler: Isshinsai Ogata aka Kensei-sama]] has taken an interest in Kenichi...
* ''MahouSenseiNegima'' plays a lot with this one, with Negi becoming apprentice to Evangeline, who holds a reputation as one of the most powerful, evil, undead vampire mage alive. Negi is fully aware of this, but trains with her anyway after deciding that [[AntiVillain she's not really ''that'' evil]]. And he seems to be right, regardless of [[NobleDemon how evil she claims to be.]]
** The whole idea is played to the hilt when Negi's childhood friend Anya shows up and discovers the identity of Negi's master. She immediately freaks out and hastily informs the girls of the danger they're in and starts to formulate a plan to escape from Evangeline without getting killed. Evangeline takes the opportunity to [[RightBehindMe sneak up behind Anya]] while in [[SleepModeSize Uber-Evil-Adult-Mode]] and scare the crap out of her.
** At one point, when Eva is mentioned, one of the girls starts [[IHaveManyNames listing off]] all of Eva's [[RedBaron names and titles]] in a bored voice to let the person know that, yes, Evangeline is ''that'' Evangeline and we are fully aware of her reputation.
[[/folder]]

[[folder:Comic Books]]
* In Wee Tian Beng's ''The Celestial Zone'', Xue Wu runs across one of these near the end of the series. Given that his insane competitiveness has been pushing him down the slippery slope—not to mention that a villain recently gave him the [[IfYouKillHimYouWillBeJustLikeHim If You Kill Me You Will Be Just Like Me]] speech right before he kebabed her—it doesn't end well.
[[/folder]]

[[folder:Fairy Tales]]
* In ''[[http://www.surlalunefairytales.com/authors/asbjornsenmoe/farmerweathersky.html Farmer Weathersky]]'', the boy's master teaches him magic but will keep him forever unless his father can find and recognize him, which he manages only with difficulty. Father Weathersky then tries to get the boy back with trickery.
* In ''[[http://www.surlalunefairytales.com/authors/grimms/68thiefmaster.html The Thief and His Master]]'', the father only has to pay if he can't recognize his son, but the master uses magic to prevent him. And when the father succeeds, he tries to reclaim the boy.
[[/folder]]

[[folder:FanFiction]]
* Daniel to Danny in the DannyPhantom fanfic [[http://www.fanfiction.net/s/4350896/1/Daniel_Masters Daniel Masters]]. Slightly played with in that Daniel believes in BlackAndGreyMorality. He teaches Danny about some abilities, but--because he actually respects Danny's character--won't teach him the more... ''deadly'' skills until Danny asks.
[[/folder]]

[[folder:Films]]
* Obviously, Anakin Skywalker and Chancellor Palpatine of ''StarWars'': "I can teach you things you need to know in order to save Padme. Oh, and you'll have to kill a bunch of kids for me too, but never mind that now..."
** This actually happens so often in the Extended Universe (to Ulic Qel-Droma, Luke Skywalker, Jacen Solo...), it's practically a trope of its own.
* ''TheKarateKid, part 3'' had Mr. Silver, slowly training Daniel to become more and more vicious in his fighting tactics. This climaxes when Daniel punches another guy in the nose at a dance, which makes him realize [[MyGodWhatHaveIDone what he has done]].
* Jade Fox in ''CrouchingTigerHiddenDragon''.
* Los Angeles Narcotics Detective Alonzo Harris from ''TrainingDay'' is THE poster boy of this trope.
* Henri Ducard / [[spoiler:Ra's al Ghul]] in ''[[TheDarkKnight Batman Begins]]''.
[[/folder]]

[[folder:Literature]]
* Justin [=DuMorne=], Harry's tutor in ''TheDresdenFiles''. Later in the series, the fallen angel Lasciel attempts to become an EvilMentor by teaching Harry how to power his spells with literal hellfire.
* TeresaEdgerton's ''[[{{Celydonn}} The Castle of the Silver Wheel]]'': the dwarf Brangwengwen plays this straight with Gwenlliant - Brangwengwen, a partially trained, elderly witch, knows the castle well enough to get into the Princess Diaspad's old rooms and thus to her old spellbooks (which feature BlackMagic), and offers instruction in witchcraft to Gwenlliant (who otherwise has no teacher, and few people to talk to).
* In ''In the Midnight Hour'' by Patti O'Shea, Ryne's mentor Anise turns to the dark side. Ryne doesn't know for sure during her years-long training period with Anise that she's secretly evil, but eventually figures out that she must have been bad all along. (You'd think Anise's kinky bedroom antics would have been a clue.) As the person closest to her, Ryne is assigned to be the one who takes Anise down, and she's afraid that she may turn to the dark side as well.
* Another EvilMentor's Book is the annotated Potions textbook in ''HarryPotter and the Half Blood Prince'': Harry has no idea what one of the spells written in the book does until he uses it on Draco Malfoy and severely injures him. However Malfoy ''was'' trying to cast an [[BlackMagic Unforgivable Curse]] on Harry at the time.
* Falcone in the ''WarchildSeries'' plays this role for Yuri. He attempts it with Jos and Cairo, too, but they don't jump at his call and both reject his teachings at once. Only Yuri follows Falcone's training and instruction without protest.
* Joruus C'baoth in TheThrawnTrilogy calls Luke to him, and for a few days Luke follows him around trying to learn from him, but quickly comes to believe that C'baoth was insane and had possibly fallen to the Dark Side. C'baoth believes himself to be the ultimate authority, naturally above those who are not Jedi. This is cinched when Luke tries to leave with Mara Jade and they are attacked, and later when they find that he was working with Thrawn.
** Interestingly played with in OutboundFlight, with Jorus C'baoth ([[CloningGambit the original]]) and his interest in the fourteen-year-old Anakin Skywalker. The original C'baoth had a superiority complex and beliefs [[InTheBlood much like his clone's]], though slightly less obvious. Obi-Wan is uneasy about this. Anakin, in some of the most subtle this-kid-isn't-gonna-turn-out-right characterization in or out of the ExpandedUniverse, thinks that C'baoth is awesome. He solves things so ''quickly'', and he doesn't take nonsense from anyone.
[[/folder]]

[[folder:Live Action TV]]
* On ''BuffyTheVampireSlayer'', Professor Maggie Walsh epitomizes this trope.
* Averted with Zaan in ''{{Farscape}}''. She had to learn both offensive PsychicPowers and become willing to use them to beat the episode's BigBad, both painful since she was a TechnicalPacifist. Her teacher at the time was more of a ZenSurvivor than evil though, but his lessons led to her using her abilities more assertively in later seasons.
* In Season 2 of ''Series/{{Heroes}}'', BigBad Adam Monroe takes under his wing resident IdiotHero Peter Petrelli, successfully [[ManipulativeBastard manipulating]] him into furthering his plans to release an apocalyptic virus upon the Earth.
* Ruby of ''{{Supernatural}}'', even if her intentions are good (and they may not be).
** [[spoiler: They're not.]]
[[/folder]]

[[folder:Theatre]]
* Roy Cohn to Joe Pitt in ''AngelsInAmerica''. Despite being a hideously loathsome man, he has a genuine affection for Joe, and offers him much in the way of (what he thinks of as) advice, which later leads to problems when Joe refuses to believe his "questionable but good-at-heart" mentor could do the kind of horrible things Roy Cohn [[RealityEnsues really did]].
[[/folder]]

[[folder:Video Games]]
* Kreia from ''{{Knights of the Old Republic}} II''. She states fairly early that she used to be a Sith, and tries to impart upon the main character the lessons of self-reliance, how doing good rarely solves anything, manipulating others to do your bidding, and a whole lot of other lessons that run contrary to the Jedi code. [[spoiler:She is also the BigBad, but unlike a TreacherousAdvisor she never uses her mentor position to backstab the protagonist, as she actually cares for The Exile.]]
* Riku in the ''KingdomHearts'' series had this as a recurring problem. The power he learned from Maleficent and Ansem was too useful not to use, but gave him serious self-image issues.
* Goutetsu in ''StreetFighter'', who taught a form of martial arts that used murderous intent in every move. Two of his students were Gouken and Akuma; Gouken purged the murderous aspects of the martial art and went on to teach this form to his students RyuAndKen, while Akuma used the form as it was intended. Akuma used it to kill Goutetsu (who died happy, knowing his legacy would carry on through his student) and later tried to pass it on to Ryu.
* Oh come on! ''{{Fable}}'' has only just been mentioned?
[[/folder]]

[[folder:Western Animation]]
* Malchior in ''TeenTitans'':
-->'''Raven:''' It's dark magic! You've been teaching me dark magic!\\
'''Malchior:''' Is it dark, or is it simply misunderstood... like you?
** Slade and Brother Blood, too, at various points. Heck, Blood does this ''for a living''.
* ''{{Avatar the Last Airbender}}'': Katara meets Hama, a waterbender from their South Pole tribe, who uses her waterbending to take control of other peoples' bodies by "bending" the water inside their blood, and uses this power on innocent people in the Fire Nation town where she lives in revenge for her tribe being imprisoned by the [[TheEmpire Fire Nation]]. Katara is horrified and refuses to learn, but in the end must resort to using it on the Evil Mentor in order to save Sokka and Aang.
* Chase Young of ''XiaolinShowdown'' repeatedly tries to recruit Omi as his apprentice.
** This reminds me of ''TeenTitans'' above, very explicitly stated as Slade's goal with Robin. (apparently...).
* PsychoForHire Lockdown plays this for Prowl in one episode of ''TransformersAnimated''.
* ''CodeLyoko'': Franz Hopper's diary accidentally becomes an evil data disk for Jérémie when he tries a technique... that almost kills him.
* During one episode of ''KimPossible'', [[HypercompetentSidekick Shego]] became the EvilMentor for Señor Senior, Jr. It worked very well, he transformed from MinionWithAnFInEvil to WorthyOpponent, until he was defeated by a DeusExMachina, and his newly found evil skillz [[StatusQuoIsGod were never mentioned ever again]].
* This is exactly what BigBad Vlad Masters wants to accomplish with Danny in ''DannyPhantom''. He only mildly succeeds because Danny [[MythArc goes through a]] [[StartOfDarkness dark arc]].
* Marathon loves this one. Diana Lombard had an evil mentor in ''Martin Mystery'' [[spoiler: which ended up with her turned into a [[CuteMonsterGirl lizard-esque creature]]]], and a minor character became "Admiral Admirable" with the help of one in ''TotallySpies!''
[[/folder]]

----
<<|{{Mentors}}|>>
<<|{{Villains}}|>>